{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.1.3"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "d7aa3a197d15c75a65b24f796d3a69f83806d3f8"
            },
            {
              "fixed": "e278bc05cc937ecd1ee62bc6a058db3a21e66614"
            }
          ],
          "repo": "https://github.com/miurahr/py7zr",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-h4gh-22qq-72r7"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-407"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55206.json"
  },
  "details": "py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, PackInfo._read() in archiveinfo.py used an O(n^2) cumulative sum pattern for attacker-controlled numstreams values parsed from archive headers, allowing a crafted .7z archive to cause excessive CPU consumption during SevenZipFile.init() before extraction. This issue is fixed in version 1.1.3.",
  "id": "CVE-2026-55206",
  "modified": "2026-07-15T01:49:06.371764373Z",
  "published": "2026-07-08T20:32:09.905Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/miurahr/py7zr/releases/tag/v1.1.3"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55206.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/miurahr/py7zr/security/advisories/GHSA-h4gh-22qq-72r7"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55206"
    },
    {
      "type": "FIX",
      "url": "https://github.com/miurahr/py7zr/commit/d7aa3a197d15c75a65b24f796d3a69f83806d3f8"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "py7zr: O(n^2) algorithmic complexity DoS in PackInfo._read()"
}